From 5232f069fbf136bcf9253cb7d271d5461a7ff162 Mon Sep 17 00:00:00 2001
From: Jaime Humberto Macias Bustamante <jamextreme140@outlook.com>
Date: Thu, 17 Jul 2025 14:46:12 -0700
Subject: [PATCH] final classes + improved custom class aliases

---
 hscript/CustomClassHandler.hx | 12 +++++++++---
 hscript/Interp.hx             | 16 +++++++++++-----
 hscript/Printer.hx            |  5 ++++-
 3 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/hscript/CustomClassHandler.hx b/hscript/CustomClassHandler.hx
index 65afe6e..9566181 100644
--- a/hscript/CustomClassHandler.hx
+++ b/hscript/CustomClassHandler.hx
@@ -10,6 +10,7 @@ class CustomClassHandler implements IHScriptCustomConstructor implements IHScrip
 	public var fields:Array<Expr>;
 	public var extend:Null<String>;
 	public var interfaces:Array<String>;
+	public final isFinal:Bool;
 
 	public var cl:Dynamic;
 
@@ -18,16 +19,21 @@ class CustomClassHandler implements IHScriptCustomConstructor implements IHScrip
 
 	public var __allowSetGet:Bool = true;
 
-	public function new(ogInterp:Interp, name:String, fields:Array<Expr>, ?extend:String, ?interfaces:Array<String>) {
+	public function new(ogInterp:Interp, name:String, fields:Array<Expr>, ?extend:String, ?interfaces:Array<String>, ?isFinal:Bool) {
 		this.ogInterp = ogInterp;
 		this.name = name;
 		this.fields = fields;
 		this.extend = extend;
 		this.interfaces = interfaces;
+		this.isFinal = isFinal != null ? isFinal : false;
 
 		if(extend != null) {
-			if(ogInterp.customClasses.exists(extend))
-				this.cl = ogInterp.customClasses.get(extend);
+			if(ogInterp.customClasses.exists(extend)) {
+				var customCls:CustomClassHandler = ogInterp.customClasses.get(extend);
+				if(customCls.isFinal)
+					ogInterp.error(ECustom('Cannot extend a final class'));
+				this.cl = customCls;
+			}
 			else 
 				this.cl = Type.resolveClass('${extend}_HSX');
 
diff --git a/hscript/Interp.hx b/hscript/Interp.hx
index 71af3ef..a931466 100644
--- a/hscript/Interp.hx
+++ b/hscript/Interp.hx
@@ -702,9 +702,10 @@ class Interp {
 		var e = e.e;
 		#end
 		switch (e) {
-			case EClass(name, fields, extend, interfaces):
-				var hasAlias:Bool = (setAlias != null && beforeAlias == name);
-				var toSetName:String = hasAlias ? setAlias : name;
+			case EClass(name, fields, extend, interfaces, isFinal):
+				var oldName:String = name;
+				var hasAlias:Bool = (setAlias != null && beforeAlias == oldName);
+				var toSetName:String = hasAlias ? setAlias : oldName;
 
 				if (customClasses.exists(toSetName))
 					error(EAlreadyExistingClass(toSetName));
@@ -715,8 +716,13 @@ class Interp {
 					final variable:Class<Any> = variables.exists(thing) ? cast variables.get(thing) : null;
 					return variable == null ? thing : Type.getClassName(variable);
 				}
-				customClasses.set(toSetName, new CustomClassHandler(this, name, fields, importVar(extend), [for (i in interfaces) importVar(i)]));
-				if(hasAlias) setAlias = null;
+				var cls:CustomClassHandler = new CustomClassHandler(this, oldName, fields, importVar(extend), [for (i in interfaces) importVar(i)], isFinal);
+				customClasses.set(toSetName, cls);
+				if(hasAlias) {
+					customClasses.set(oldName, cls); // Allow usage in the same module
+					beforeAlias = null;
+					setAlias = null;
+				}
 			case EImport(c, n, isUsing):
 				if (!importEnabled)
 					return null;
diff --git a/hscript/Printer.hx b/hscript/Printer.hx
index 1189dc2..58bee51 100644
--- a/hscript/Printer.hx
+++ b/hscript/Printer.hx
@@ -120,7 +120,10 @@ class Printer {
 			add('${u ? 'using' : 'import'} $c');
 			if(n != null)
 				add(' as $n');
-		case EClass(name, fields, extend, interfaces):
+		case EClass(name, fields, extend, interfaces, fnal):
+			var isFinal = fnal != null && fnal;
+			if(isFinal)
+				add('final ');
 			add('class $name');
 			if (extend != null)
 				add(' extends $extend');